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MAF sensor relay help

mikevochis

Member
Joined
Jun 8, 2002
Messages
20
Location
CT
Corvette
03 50th Convert, 91 & 94 coupes & 96 Collectors
I decided to change the MAF power and burnoff relays on my 86 vette do to a hard start condition. My local dealer sold me 2 with the p/n 10067925. I put both in and the check engine light came on and the RPM's were all over the place. As soon as I put the old ones back in the light went off and car ran fine. In the back of my chevy parts book it calls for two of the same relays, but in the front it calls for two different ones. P/N 10067925 and P/N 10094701. Any help would be greatly appreciated.
 
T

Tonylong

Guest
BTT I'd like to follow on this thread, I believe I have a similar problem
with my '89 and ai wan to know about the part nos. too.
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
I wish I could help you with this, but maybe c4c5specialist will see this soon and impart his advice on the subject. He is a very knowledgeable mechanic. (Or should I say "Technician" Paul?) :L

_ken :w
 

mikevochis

Member
Joined
Jun 8, 2002
Messages
20
Location
CT
Corvette
03 50th Convert, 91 & 94 coupes & 96 Collectors
Still need a little help...

I got the two different relay's but I can't tell which one goes where. The power and burnoff relay's look the same. Both relay's have 5 pins, but one plug has 5 pins and the other only has 4. Does anyone know how I can tell which is the power and which is the burnoff connector.
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
On an 88

Which I believe to be same on yours

The one closest to the engine is the
MASS BURN OFF RELAY

Which makes the other one
MASS BURN OFF CONTROL RELAY.


Diggin in further


Vig!
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Ok relay pin outs & functions

The control relay..

Single pole DOUBLE THROW relay

Purple wire [Power to MAF]
relay socket pin E
(relay pin 5)
Swinger in relay

Dk Blue wire [Junction to Mass burn off relay pin E & to MAF pin D]
relay socket pin C
( relay pin 2)
N.C. in relay

Orange wire [Power From BATT]
relay socket pin A
(relay pin 1)
N.O. in relay

Red wire [Power From Oil pressure switch]
relay socket pin D
(relay pin 3)
Coil in relay

Black wire [Ground]
relay socket pin F
(relay pin 4)
Coil in relay

Vig!
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
MAss burn off relay pin out

SINGLE POLE SINGLE THROW RELAY

THERE IS NO NORMALLY OPEN POSITION ON THIS RELAY!

SO NO WIRE ON PIN C OR MAYBE NO PIN 2 HOOKED UP INTERNALLY

Dk Blue wire [Junction to Mass burn off control relay pin C & to MAF pin D]
relay socket pin E
( relay pin 5)
N.C. in relay

Orange wire [Power from batt]
relay socket pin A
( relay pin 1)
Swinger in relay

Orange wire [Power from batt]
relay socket pin D
( relay pin 3)
Coil in relay


Black wire [ground]
relay socket pin F
( relay pin 4)
Coil in relay

TADA


Vig!
 

mikevochis

Member
Joined
Jun 8, 2002
Messages
20
Location
CT
Corvette
03 50th Convert, 91 & 94 coupes & 96 Collectors
Thank you

You guy's and this site are an incredible wealth of knowledge. I'll check it out tonight and let you know how I make out. Thanks again

MIKE
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Disclaimer

Now this is off an 88 and SHOULD be the same.


A standard relay SHOULD work fine UNLESS there is an actual wire stuffed in the socket on PIN C of the Mass Burn off relay...If there is all bet's are off and you MUST get that specific relay.


That being said... a REALLY CREATIVE PERSON

Could open up a new relay and break off the normally open contact ( pin 2 of the relay) and make his ( or her own )..

But that same level of "creativity" would open up the OLD relay and burnish the contacts!


Your very welcome!

Vig!
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
So any news?

enquiring minds want to know!

Vig!
 

mikevochis

Member
Joined
Jun 8, 2002
Messages
20
Location
CT
Corvette
03 50th Convert, 91 & 94 coupes & 96 Collectors
I hope I didn't open a can of worms

I put the two relay's in as you said (nice detailed description, thank you), and started the car. I started a little hard, but no check engine light came on. The tach read a steady 700, which is normal for my car, but the idle was very "lumpy", like I put a big fat cam in. I switched the position of the relay's and the check engine light lit on start up. I then put the original relay's back in and everything was back to normal. My first thought was to clean my IAC, but the idle is ok with the original relay's. Can these relay's change my idle?? I'm open to any thoughts/suggestions. Thanks

MIKE
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Well obviously they do....

The resistance internal of the relay affects the CAL of the MAF...

Putting on thinking cap..

It looks like The mass burnoff only goes ON once & a while, but during the RUN mode The control relay would be the touchy one as far as inline resistance in the circut goes.


I would also venture that an ECM ( pull the battery ) clean out would be in order.

And an Idle relearn for ECM

Start car.. before 10 seconds shut it off and the restart & let idle.

And if you have the SPST relay and the SPDT relay swapped... yeah you will get a code.


I bought 2 NEW AC/DELCO relays
( for my fans )

And what do you think popped out of the box....

Made in CHINA!

Vig!
 

mikevochis

Member
Joined
Jun 8, 2002
Messages
20
Location
CT
Corvette
03 50th Convert, 91 & 94 coupes & 96 Collectors
Thanks Vig...

I'll try the ECM clean out sometime this week. Can I just pull the neg off or should I pull both terminals? I've been told 15-20 mins disconnected is long enough...do you agree? While I got you... I'm replacing my bilstein's this week and was wondering where I could find some good alignment specs... caster, camber etc.
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
ECM wipeout

5 min or so will do the trick.

You only NEED to pull 1 terminal


Alignment...Dunno...

Repost with

Alignment spec's & opinions needed

You get lots of info..I'm sure

Or do a search....

Vig!
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Well you have the procedures in the quote

There are MIX tables the car (ecm) learns over time which are held in ROM...

When ya pull the batt........ROM go by by....

So you default to the memcal....
(factory default settings)

You drive around until the car gets smart as it 's gonna get.

***********************************

The Idle relearn you can do at any time..

You basically stall the car with a quick shutdown..... you make the ECM go "Hmmmm! I just stalled...I better fix that"

And you crank again quickly... if you don't the ECM thinks.."Aw he ment to do that"

The ECM guesses to richen up the mix & increase the air by a little bit... and walks the car back into idle specs.


Now drive the car for a while (and get to over 40mph for a few minutes)

This forces the IAC motors shut...


Your done,


Vig!
 

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